The present invention is directed to a method for manufacturing plastic drums, and more particularly, to a method for joining two components to form a plastic drum.
Plastic drums are typically used to store and transport a wide variety of materials, including fluids as well as dry and powdered materials. Existing plastic drums are typically formed by blow molding, which forms the drum as a single, unitary piece of plastic. However, blow molding drums requires a relatively high weight of materials, has a long cycle time (i.e. up to several minutes per drum), and does not provide precise tolerances in the finished drum. It is known that producing parts by injection molding may reduce cycle times and the weight of the required materials. Injection molding also produces higher-precision parts. However, it is not practical to injection mold a single, unitary drum. Instead, two or more injection molded parts must be joined together to form a drum. The separate parts must be joined together with sufficient strength to ensure that the resulting drum can withstand various forces, such as internal pressure forces and/or external forces applied to the drum during loading, transportation, and the like. Accordingly, there is a need for a method for joining two components together to form a plastic drum in a quick and efficient manner such that a strong connection is formed between the two components to form a durable, robust drum.
The present invention is a method for joining two components together to form a durable, robust plastic drum in a quick and efficient manner such that there is a strong connection between the components of the drum.
In a preferred embodiment, the invention is a method for forming a plastic drum comprising the steps of selecting a lower component having a bottom and a generally cylindrical side wall, the side wall defining an opening, and selecting an upper component having a center section and an annular end portion, the end portion having an annular slot. The method further comprises the step of locating the upper component on the lower component such that the upper component covers the end opening and such that at least part of the side wall of the lower component is received in the annular slot, and welding the portion of the side wall received in the annular slot to the upper component.
Accordingly, it is an object of the present invention to provide a method for joining two components together to form a plastic drum in a quick and efficient manner such that there is a strong connection between the two components. Other objects and advantages of the present invention will be apparent from the following description and the accompanying drawings.